Last year was the most perilous ever for people defending their community’s land, natural resources or wildlife, with new research showing that environmental defenders are being killed at the rate of almost four a week across the world.

Two hundred environmental activists, wildlife rangers and indigenous leaders trying to protect their land were killed in 2016, according to the watchdog group Global Witness – more than double the number killed five years ago.

And the frequency of killings is only increasing as 2017 ticks by, according to data provided exclusively to the Guardian, with 98 killings identified in the first five months of this year.

John Knox, UN special rapporteur on human rights and the environment, said: “Human rights are being jettisoned as a culture of impunity is developing.

“There is…